Experimental and Finite Elements Analysis of Bondline Flaw Criticality in Composite Scarf Joints

Abstract

Conventional design methods for bonded repairs to composite structure assume that the repair is in pristine condition. However, for a repair to be certified on primary structure, the repair must be designed to address damage tolerance and fatigue strength requirements, in addition to static strength. Therefore, the criticality of bondline flaws in composite scarf joints is analysed within this paper using finite element analysis (FEA). Experimental data is presented for scarf joints with various initial flaw sizes. As a result of both the experimental and FEA studies, it can be concluded that the strength of a scarf joint is considerably and adversely affected by the presence of a flaw.